22 Jul
2018
22 Jul
'18
10:54 a.m.
From: Mark Matlock
With the 11/83 the position of the memory board ...
above the CPU uses
PMI
Yes, through the C-D interconnect; described in detail here:
http://gunkies.org/wiki/CD_interconnect#Use_by_PMI
The 'above' is because the CD interconnect is not a true bus, it only
interconnected pairs of slots.
In the 11/84 the CPU is above the MSV11-JE memory
The PMI is still on the CD connector in this machine, but the PMI is wired as
a true bus on the backplane, allowing that ordering.
there are 3 Bus slots in the 11/84 above the Unibus
map board, would it
be possible to put a dual width Q22 I/O board in the second memory slot
(not the PMI side of the slot) and have it able to DMA into the
MSV11-JE?
It is speculated that this should be possible, but there are jumpers on the
backplane you'd need to pull. See the writeup here:
http://gunkies.org/wiki/PDP-11/84#QBUS_slots
Noel